Victory over Li Na sets up rematch of 2012 final

Serena Williams maintained her quest for a fifth U.S. Open title with a confident semifinal victory over Li Na at Flushing Meadows on Friday.

The world No. 1, who overcame Victoria Azarenka in last year's final and will face the Belarusian again in a rematch on Sunday, is still yet to drop a set in this year's tournament after crushing the fifth seed, 6-0, 6-3 in a mere 89 minutes.

Serena Williams lunges as she hits return against Li Na. Williams continued her domination at the U.S. Open on Friday. (AP Photo)

Williams never looked like succumbing to a shock in what was a near-perfect performance, the 31-year-old hitting 19 winners and winning 76 percent of points on her first serve.

Li headed into the encounter on the back of an unconvincing three-set win over Ekaterina Makarova, and she proved no match for the 16-time grand slam champion in the first set.

Once again Williams' powerful ground strokes were the difference between the two players, the American completely dominant as she refused to allow her Chinese opponent to get on the board in the opener.

The world No. 6 did provide more resistance in the second, and looked to be on her way to leveling the match when she broke Williams' serve to take a 2-1 lead.

Those hopes were quickly put to bed as Williams took the next four games to put herself on the verge of victory.

Li, however, refused to go down without a fight, the 2011 French Open champion saving six match points to hold serve and keep her slim hopes intact.

That stout defenae did little more than delay the inevitable, though, as Williams duly closed things out at the seventh opportunity with a perfect serve that Li could only send into the net.

Williams admitted that nerves did get to her in the closing stages of the match, but is looking forward to facing Azarenka, who beat Flavia Pennetta, 6-4, 6-2.

"It was a good match, Li Na is such a great player, it was tough at the end," Williams said.

"I got a little nervous, but I was able to close it out in the end, finally.

"We (Williams and Azarenka) always have really good matches, it's great just to get another final."